Heretofore available as devices for automatically making continuous mounting of different types of electronic parts such as a resistor (FIG. 1a), a diode (FIG. 1b), etc., were those which were roughly categorized into two types by the feeding method of the aforementioned electronic parts.
Known inserting devices include a first system in which, for example, an assembly is prepared wherein electronic parts, which are different in type, are arranged in a band shape beforehand in the order of their insertion; such an assembly is directly fed to an insertion head, to make successive insertion of the parts (FIG. 2).
On the other hand a second system is available in which assemblies of the needed types of electronic parts are prepared, same type of electronic parts in a band shape; at the times of inserting respective electronic parts, such assemblies are selected in the order of insertion and the needed electronic part at a time is separated from each of the aforementioned assemblies and such parts are, then, conveyed to the insertion head for their insertion by means such as a belt, pipe, etc. These methods have the following disadvantages, respectively:
Thus in the first system, a plurality of different types of parts need to be prepared as an assembly in a taping band shape; in such an assembly, their replacement can not be made, if insertion mistakes have occurred in any circumstances.
On the other hand, in the second system, because of the use of a conveyor or pipe, its turning or tilting while conveying the parts interferes with their stable feeding to the insertion head. Furthermore, because a long time is taken to transport the parts, the number of insertion cycles of the parts can not be increased. Moreover, outer walls of the conveyor and pipe tend to injure parts or deform lead wires.
Against this background, there has already been proposed and put into practical use a new type of inserting device capable of solving such disadvantages of the aforementioned devices adapted for continuous insertion of different types of parts. This device employs the type of arrangement disclosed in U.S. Pat. No. 4205433 in which a means is provided for holding a plurality of taped assemblies side by side, each assembly comprising electronic parts of same type and transferring one of the aforementioned plurality of electronic part assemblies to the specified position for feeding the part. In addition an insertion head makes a reciprocal motion between the aforementioned part feeding position and the position adjacent a printed substrate, located apart from the part feeding position, to transfer the single electronic part which has been cut off the electronic part assembly at the part feeding position to a position in proximity to the printed substrate and at this latter position, the electronic part is inserted into the aforementioned printed substrate. This system is called random access type, as against the sequential type of the aforementioned first system. The insertion device of this system has outstanding effects in response to insertion mistake of electronic part and stability in insertion.
On the other hand, in the advancing field of automation by use of such mounting devices of electronic parts, needs exist not only for stabilization of arrangement but for dealing with the project of growing forming lines with various types of automatic mounting devices and there is a demand for development of mounting devices which are to be designed for high work efficiency in totality through effective utilization of machine installing space and improvement in productivity.
With regard to the device disclosed by the aforementioned U.S. Pat. No. 4205433, a plurality of electronic part assemblies are mounted parallel to each other on a movable stand in one direction; the movable stand is moved along a straight line to bring a specified part to the vicinity of the insertion head position, which requires a large space in the length direction of the machine, raising the problem of the whole size of the machine becoming too large. In addition a tape feeding unit is fixed to the movable table, causing trouble in displacement of parts and low workability; moreover, the tape scraps produced after the taped electronic parts have been inserted are discharged as they are; this poses the problem of such tape scraps coiling around the tape feeding unit, when it is attached or detached.
In connection with the problem of space mentioned above, a device for providing a more advantageous system is disclosed by Japanese Patent Gazette No. 66466 of 1979. In this device, the electronic part assemblies are placed further outside the tape feeding unit which is located at the outer periphery of a movable stand in the shape of a circular table and an insertion head provided with a turret type insertion chuck mechanism effects sequential insertion of electronic parts.
This device has such disadvantages as hereunder enumerated: First, a cartridge type arrangement is formed by unifying the tape feeding unit and the electronic part assemblies, but this requires time in their attaching and detaching. Secondly, for performing tape scrap disposal, tape cutting mechanisms are equipped in all tape feeding units mounted on the circular table, resulting in high manufacturing cost. And thirdly, in the event of a mistaken insertion, while the inserting device is in operation, the same parts can not be resupplied, because of the sequential insertion of electronic parts.